kernel-packages team mailing list archive

[Launchpad Bug Tracker <1098342@xxxxxxxxxxxxxxxxxx>]

[Expired for linux (Ubuntu) because there has been no activity for 60
days.]

** Changed in: linux (Ubuntu)
       Status: Incomplete => Expired

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1098342

Title:
  out of memory errors when performing I/O on a system with large amount
  of RAM and 32-bit pae kernel

Status in “linux” package in Ubuntu:
  Expired

Bug description:
  We have a system with 64GB of RAM which we have to run with a 32-bit
  installation for various reasons. When performing I/O on that system,
  we suddenly get "Out of memory" errors, and if I/O is fast enough
  (i.e. cat /dev/zero > /dev/shm/somefile), the system becomes unusable
  very quickly. The following list of example commands will cause an OOM
  condition at various speeds:

  # Causes OOM and complete denial of service within 10-15 seconds:
  cat /dev/zero > /dev/shm/somefile

  # Causes OOM and complete denial of service within 30 - 40 seconds:
  cat /dev/zero > /dev/shm

  # Causes sporadic OOM errors:
  cat /dev/sda > /dev/sdb

  The /dev/sda and /dev/sdb devices read and write sequentially at about
  150MB/s.

  The same error was reproduced with the newest upstream 32-bit pae
  kernels from 12.10 (quantal) and 13.04 (raring). Also, the same was
  reproduced with Debian Queeze 32-bit kernel (2.6.32) installed on
  Ubuntu 12.04.

  The error appears to be absent in 64-bit kernels (installed instead of
  the 32-bit kernel on the same 32-bit Ubuntu 12.04 installation).

  Please see attached an example of OOM and DoS that was caused with
  "cat /dev/shm > /dev/shm/somefile" in the out_of_memory_errors.txt
  attachment.

  ProblemType: Bug
  DistroRelease: Ubuntu 12.04
  Package: linux-image-3.2.0-35-generic-pae 3.2.0-35.55
  ProcVersionSignature: Ubuntu 3.2.0-35.55-generic-pae 3.2.34
  Uname: Linux 3.2.0-35-generic-pae i686
  AlsaDevices:
   total 0
   crw-rw---T 1 root audio 116,  1 Jan 10 15:55 seq
   crw-rw---T 1 root audio 116, 33 Jan 10 15:55 timer
  AplayDevices: aplay: device_list:252: no soundcards found...
  ApportVersion: 2.0.1-0ubuntu14
  Architecture: i386
  ArecordDevices: arecord: device_list:252: no soundcards found...
  AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1:
  CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found.
  CurrentDmesg:
   [   11.884916] NFSD: starting 90-second grace period
   [   18.448013] eth0: no IPv6 routers present
  Date: Thu Jan 10 16:10:40 2013
  IwConfig: Error: [Errno 2] No such file or directory
  MachineType: Supermicro H8DGU
  PciMultimedia:
   
  ProcEnviron:
   TERM=xterm
   PATH=(custom, no user)
   SHELL=/bin/bash
  ProcFB:
   
  ProcKernelCmdLine: root=/dev/sda1 ro
  PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon.
  RelatedPackageVersions:
   linux-restricted-modules-3.2.0-35-generic-pae N/A
   linux-backports-modules-3.2.0-35-generic-pae  N/A
   linux-firmware                                1.79.1
  RfKill: Error: [Errno 2] No such file or directory
  SourcePackage: linux
  UpgradeStatus: No upgrade log present (probably fresh install)
  WifiSyslog:
   
  dmi.bios.date: 12/10/10
  dmi.bios.vendor: American Megatrends Inc.
  dmi.bios.version: 1.1
  dmi.board.asset.tag: To Be Filled By O.E.M.
  dmi.board.name: H8DGU
  dmi.board.vendor: Supermicro
  dmi.board.version: 1234567890
  dmi.chassis.asset.tag: To Be Filled By O.E.M.
  dmi.chassis.type: 17
  dmi.chassis.vendor: Supermicro
  dmi.chassis.version: 1234567890
  dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1.1:bd12/10/10:svnSupermicro:pnH8DGU:pvr1234567890:rvnSupermicro:rnH8DGU:rvr1234567890:cvnSupermicro:ct17:cvr1234567890:
  dmi.product.name: H8DGU
  dmi.product.version: 1234567890
  dmi.sys.vendor: Supermicro

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1098342/+subscriptions